Tag Archives: Provirus

Our genome is not ours alone

Dendrogram of various classes of endogenous re...
Dendrogram of various classes of endogenous retroviruses (Photo credit: Wikipedia)

The last twenty years have been marked by a veritable explosion in sequencing technology. The Human Genome Project and it’s completion in 2003 was the crowning jewel of this burgeoning genomics revolution and played a major role in my early introduction to science. I distinctly remember being a sophomore in high school completely fascinated with the fact that we as a species have taken it upon ourselves to read the basic text that makes us all human. It still awes me that we are capable of this level of technology and that it just keeps getting better, smaller, and faster. Case in point: I am currently sitting 20 feet from an Illumina MySeq, an object the size of a 1990s-era desktop computer capable of delivering sequencing results in 24 hours. The amount of information to come from this branch of science is literally mind-boggling and only grows with each passing day.

Interesting observations have come out of this massive amount of genomic data relating to the  non-coding DNA in our genome. Less than 2% of the over 3 billion nucleotides in our genome are responsible for coding all of the protein that makes up a human being. This leaves a large question as to what exactly that other 98% of our genome is up to. Large parts (roughly 50%) are known as “junk DNA” with no accepted role, although new research is beginning to shed light on the functions of this DNA. The remainder of our genome is composed of long and short repeated sequences, transposons, retrotransposons and the topic of today’s article: endogenous retroviruses.

These elements are not human, they are fully viral in origin. This means that our genome is not just ours alone, we carry the DNA of many viruses that infected our ancestors in every cell in our own bodies.

Keep reading to find out what an endogenous retrovirus is, why exactly these viruses have invaded our own genetic code, and the implications of this discovery for the treatment of modern retroviruses such as HIV… Continue reading Our genome is not ours alone